1. Field of the Invention
The present invention relates to a vehicular air conditioner mounted in vehicles such as automobiles.
2. Description of the Related Art
A vehicular air conditioner which can provide comfortable vehicle cabin environment to passengers by conditioning air in the vehicle cabin of automobiles comprises equipment such as: a cooling apparatus comprising a compressor which uses the engine as a drive source, a condenser, an expansion valve, an evaporator, and piping for connecting these in a circuit and which is filled with operating gas; a heater core using an engine coolant as a heating source; a casing for housing the evaporator and the heater core and forming a predetermined air flow path; an air mix damper for adjusting the air quantity passing through the evaporator and the heater core; and a blower for blowing air.
In an upstream portion of the casing, there is provided an inside air/outside air changeover damper which can change over from an outside air intake to an inside air intake, and vice versa.
As a matter of course, there is also provided a blower along of the air flow path, and suitable air outlets are fitted for blowing air towards the windshield, the driver and the feet of the driver.
If the cooling apparatus is driven so as to only operate the evaporator, cooling is effected, and if only the heater core is operated, heating is effected. If the evaporator and the heater core are both operated at the same time, cooled air can be heated to effect dehumidification.
Temperature adjustment is performed by adjusting the ratio of the air quantity passing through the evaporator to the air quantity passing through the heater core, by means of the air mix damper. If the inside air/outside air changeover damper is changed to the inside air position, air conditioning is performed by circulation taking in air in the vehicle cabin from the air intake port. If the inside air/outside air changeover damper is changed to the outside air position, air conditioning is performed by taking in outside air and blowing the conditioned air into the vehicle cabin.
For example with the above described air conditioner, in the case of a standard front-engine type sedan passenger vehicle, the air conditioner is installed in the engine room below the dashboard on an assistant driver's side as seen from inside of the vehicle cabin. In this case, the inside air intake for drawing in air from the vehicle cabin opens below the dashboard on the assistant driver's side.
With the above described air conditioner, the following operation modes can be selected by opening and closing various dampers.
"Face blowing mode" is for blowing cool air from a face air outlet toward a passengers' upper body at the time of operating the air conditioner, mainly in the summer season.
"Foot blowing mode" is for blowing warm air from a foot air outlet toward the feet of passengers at the time of heating, mainly in the winter season.
The above described conventional air conditioner can be operated by selecting either of an inside air circulating operation for drawing in air in the vehicle cabin (inside air) and blowing the conditioned air into the vehicle cabin, or an outside air introducing operation for introducing air outside the vehicle cabin (outside air) and blowing the conditioned air into the vehicle cabin, by opening or closing the inside air/outside air changeover damper.
With the above described conventional air conditioner, conditioned air can only be blown to the front seat side, and air conditioning of the rear seat side is effected by circulating air blown toward the front seat side by air currents.
Therefore, on the front seat side, air can be blown directly toward the upper body or the feet of passengers, but it is not possible to blow air directly to passengers in the rear seat.
Moreover, since the air intake port for drawing in inside air is disposed in the front lower part in the vehicle cabin, generally under the dashboard on the assistant driver's side, sufficient circulation of air may not be effected over the whole region in the vehicle cabin at the time of the inside air circulating operation. In particular, at the time of heating when, in many cases, the inside air circulating operation is performed, warm air is circulated only on the front seat side, and hence stagnation occurs on the rear seat side.
On the rear seat side there is therefore a problem in that air conditioning is insufficient, so that comfort in the rear seat is compromised.
Furthermore, in the above description, an air conditioner mounted in a front-engine type vehicle has been described. In the case of mounting the air conditioner in a rear-engine type vehicle however, it is necessary to arrange the compressor in a rear part of the vehicle body together with the engine. Therefore, the refrigerant must be piped to the front part of the vehicle from the rear part, requiring more refrigerant and piping therefor. There is thus the problem of an increase in vehicle weight.
Moreover, in the case of the rear-engine type vehicle, there is a rear-blowing type in which a cooling apparatus is installed in the trunk and an air outlet is provided in the trunk. In this case, there is a problem in that the blown air does not reach the driver's seat, and the vehicle cabin cannot be uniformly air-conditioned.